require 'mathn'
puts 'A = '
A = gets.chomp.to_i
prime_power = [1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 16, 17, 19, 23, 25, 27, 29, 31, 32, 37, 41, 43, 47, 49, 53, 59, 61, 64, 
  67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 109, 113, 121, 125, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 
  169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227]
  
prime_power.each { 
  |prime| if prime < A 
    print prime
   end
   print " "  
}